Lipids

• Roles of waxes

  • melt under 45°C
  • waterproofing

  leaf cuticle and insect exoskeleton
• What does unsaturated fat in diet do?

  increase unsaturated fats = increase LDL

  carries LDL to liver for disposal

  increase HDL:LDL ratio

  decrease risk of cardiovascular disease
• Properties of unsaturated fats

  • single C -C bonds
  • fatty acid chains
  • solid at room temp
  • stored energy in mammals
• Properties of unsaturated fats

  • double c-c bonds
  • liquid at room temp
• Cause, factors and effects of high saturated fat diet?

  • lifestyle (age, smoking, lack of exercis, saturated fats die)
  • increase LDL -> cause atheroma
  • could cause blocked coronary artery -> heart attack
• Describe a phospholipid

  • one phosphate hydrophillic head
  • two fatty acid tails
  • glycerol backbone
• Good + Bad cholesterol & how made

  • lipids + proteins -> lipoprotein (LP) in small intestine
  • high density lipoprotein (HDL) -> good
  • low density lipoprotein (LDL) -> bad
• atherosclerosis = coronary heart disease
• Hypertension = high blood pressure
• Atheroma = fatty build up in coronary artery
• Angina = chest pain

  • heart contraction -> restricted blood flow
• Myocardial infraction = coronary artery blocked -> leads to cardiac arrest
• Roles of Phospholipids

  • phospholipid bilayer - membranes
  • electrical Insulation - nerve cells
• Roles or Triglycerides

  • energy reserves - more ATP than protein
  • thermal insulation
  • protection - vital organs
  • metabolic water
  • buoyancy
• Condensation reactions triglycerides

  C3H8O3 + C6H12O2 -> triglycerides

  glycerol 3x fatty acid tails

  
• Tests for fats/oil:

  • mix fat/oil with absolute alcohol in a boiling tube
  • shake the tube
  • pour mixture into another boiling tube half full of cold water
  • if lipids are present, cloudy white emulsion will form